<!--
	来源:CSS世界11页
	网址:http://demo.cssworld.cn/2/2-1.php
	说明:火狐的未定义行为
-->
<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style>
.active-btn {
    display: inline-block; 
    background-color: #fff;
}
.active-btn:active {
    background-color: #000;
}
</style>
	</head>
	<body>
<a href="javascript:" id="button" class="active-btn">按下</a>
<script>
	var button = document.getElementById("button");
if (button.addEventListener) {
    button.addEventListener("mousedown", function(event) {
        // 此处省略N行
        event.preventDefault();    
    });
}
</script>
	</body>	
</html>
